Method and apparatus for the production of combustible gases from liquid fuels



Aug. 3M, 1955 w. LINDER 2,716,597

METHOD AND APPARATUS FOR THE PRODUCTION OF COMBUSTIBLE GASES FROM LIQUIDFUELS Filed June 12, 1951 Sm ento United States Patent 0 9 (Ilaims. (Cl.48-62) assignor, by mesne as- Pittshurgh, Pa,

The invention generally relates to the continuous production ofcombustible gases-particularly gases of high calorific value which canalso be used as town gasfrom liquid fuels such as mineral oil, coal taroil, browncoal tar oil, tar oils from low temperature carbonisation, andresidues or distillates from the distillation of such or other liquidfuels. More specially the invention relates to a process for theproduction of combustible gases from liquid fuels wherein the liquidfuel is converted by reaction with oxygen and, if desired, steam in areaction chamber operating at a high temperature.

It has been already proposed to convert liquid fuels into combustiblegases by reaction with oxygen and'steam in such a Way that the reactioncomponents are injected independently and separately in form of jetsinto a reaction chamber at high temperature. The gases resulting fromsuch mode of operation, though combustible, do not show such calorificvalue and such density as have been found to be necessary for using suchgases for heating and lighting in place of coal carbonisation gases suchas town gas. Another disadvantage of the known manner of operation asdescribed above is to be seen in the face that a rather large amount ofelementary carbon such as soot is formed.

In contrast to this prior art the invention consists in the productionof combustible gases from liquid fuels in such a way that only a portionof the liquid fuel to be gasified is caused to react directly withoxygen in order to produce continuously gases, preferably combustiblegases of high temperature and after that introducing before cooling intothe flow of hot gases the other portion of the fuel, preferably in acontinuous stream.

This principle of operation according to the invention may be reduced topractice in different ways. One way consists in introducing into thereaction chamber the liquid fuel in finely divided, but liquid, formviz. one portion in mixture with gaseous oxygen and the other por-Patented Aug. 30, 1955 "ice converted with oxygen respectively to beintroduced into the flow of hot reaction products. Physical qualities tobe considered here are the density and the calorific value of the gasesproduced.

Furthermore the invention allows producing in one operation from liquidfuels a valuable fuel gas of town gas quality.

The mode of operation as described may be performed at normal pressureas well as at increased pressure.

Although the invention is related principally to the treating of liquidfuels it is, however, possible to replace at least part of the liquidfuel by such gaseous fuels the calorific value of which is high becauseof their contents of high molecular hydrocarbon gases which may becracked to form permanent gases or low molecular hydrocarbons.

Gases to be considered here are, for instance, natural gases containingpropane, butane etc.

In case that the fuel to be treated according to the invention shows arelatively small content in disposable hydrogen the useful fuel gasformed may have a higher density than desired. In order to compensatethis un' desired property of the valuable gas it is possible to convertby well-known process at least part of the carbon monoxide of thevaluable gas into carbon-dioxide and free hydrogen, removing as far asit is necessary out of the gas the carbon dioxide resulting from suchconversion by means of washing the gas at increased pressure.

It may be mentioned that the term oxygen" includes pure oxygen as wellas air enriched in oxygen.

In the accompanying drawing forming part of this specification there isshown for purposes of exemplifi cation a preferred form of apparatus inwhich the invention may be embodied and practised. The drawing shows adiagrammatic fiow sheet in vertical section of apparatus for carryingout the improvement provided by the present invention.

The apparatus essentially consists in two equipments, the reactionchamber 1 and the heating and evaporating equipment 2. The walls 3 ofthe reaction chamber 1 are constructed of refractory material which isheated to a high temperature level by the heat produced in the reactionchamber and which maintains the high temperature in the reaction chamberbecause of its low thermal conductivity. In the lower part of thereaction chamber 1 a series of recesses 4 having the shape of a tionwithout addition of oxygen at a place or places which I are more or lessspaced from the inlet of the fuel-oxygen mixture.

Another mode of realization of the invention consists in vaporizing oneportion of the liquid fuel to be gasified by a distillation or any othersuitable manner of evaporation in order to produce hydrocarbon vaporsfor mixing with the flow of hot combustible gases resulting from thereaction with oxygen of the other vaporized portion of the liquid fuel.

The reaction with oxygen of the fuel to be gasified and the followingcracking of the hydrocarbons injected into the hot reaction products maybe performed in presence of steam, if desired.

The essential advantage of the process according to the invention is tobe seen from the fact, that it is possible, when operating in the givenmanner, to produce valuable gases or mixtures of gases of preferredcompo sition and physical qualities by suitably adjusting the amount ofoxygen and, if any, steam to be added to truncated cone are providedwhich open to the reaction chamber. The smaller base of the recesses 4shows one or more holes which are connected with injector nozzles 5, thelatter extending at a short length into the free space of the respectiverecess. Instead of coordinating one nozzle to each recess it is alsopossible to provide a series of nozzles forming a bundle, the mouth ofthe nozzles of each bundle lying in one plane within the hollow of therecess.

Oxygen or air enriched in oxygen is fed through line 0 into the nozzle 5whilst the liquid fuel after being heated in the equipment 2 is fedthrough line 7. The flow of oxygen while passing through the nozzle line5 catches the liquid fuel from line 7, thus forming a homogeneousoiloxygen mixture which is injected in form of a jet into the reactionchamber. By influence of heat radiation from the hot chamber walls themixture is ignited and the reaction between fuel and oxygen can takeplace. The ratio of fuel to oxygen is adjusted in such a way thatpreferably a combustible gas or a mixture of such gases is formed thefuel and the total amount of fuel which is to be which naturally has avery high temperature.

The gas mixture produced in this reaction ascends in the reactionchamber and reaches the area of the nozzles 8 at half of the totalheight of the reaction chamber. The nozzles 8 serve for the introductioninto the hot reaction products from the primary zone of fuel vapourswhich are fed by line 9. When contacting the hot reaction products thefuel vapours injected by nozzles 8 are likewise heated and thensubjected to a thermal cracking process by which process the fuelvapours are cracked forming principally permanent gases, such ashydrogen and carbon-dioxide besides a certain amount of low boilinghydrocarbons such as methane. The combined gas mixture escapes throughoutlet opening 10 for any use or further treatment. The solid reactionproducts i. e. ash, elementary carbon, fall down into lowest part of thereaction chamber from which they may be withdrawn continuously or batchwise through opening 11. The pre-treatment of the liquid fuel to begasified is performed in the heating and evapourating equipment 2. Asshown in the drawing the heating and evaporating equip ment 2 comprisesa fire box 12 and a kettle 13 in which heating and evaporatingrespectively of the liquid fuels happen. The fire box 12 is equippedwith nozzles 14 for injecting an oil-air mixture on gas-air mixturewhich is ignited and burnt developing a large amount of heat. The burntor waste gases leave the fire box by ascending through a vertical systemof fire or smoke tubes 15 and are gathered in the collector space 16from which they escape into the chimney stack 17. A throttle 18 in thechimney 17 serves for regulating the draught.

The liquid fuel oil to be treated is fed into the kettle 13 through line19 and is filled up to a level 20. A free space 21 is provided above theliquid fuel level in the kettle 13. In this free space the fuel vapoursfrom the liquid fuel which has been evaporated by indirect heat exchangewith the hot combustion gases from fire box 12 are gathered and thendrawn off through line 9 to the injector nozzles 8.

The heated but still liquid fuel oil leaves the kettle 13 through line 7and is injected after mixing with oxygen from line 6 through nozzles 5into the recess 4 of the reaction chamber 1.

The temperature of the waste gases in the kettle 13 is adjusted withregard to the desired ratio of liquid fuel to fuel vapour. Moreover thetemperature to be maintained must conform to the specific physical andchemical proprties of the liquid fuel to be gasified. A most simplemanner of regulating the temperature of the waste gases in the firetubes 15 consists in recycling part of the waste gases of the chimney byline 22 comprising a regulating valve 23 to the fire box 12.

The useful gas is drawn off from the reaction chamber 1 through outlet10 with a comparatively high temperature. In order to improve theeconomy of the process according to the invention it has been foundadvantageous to perform the heating and vaporizing respectively of theliquid fuel in the kettle 13 at least partly by passing the hot usefulgases after escaping the reaction chamber 1 through the heating pipes 15of the kettle 13 before they are used or treated for any purpose.

In case that the fuel to be injected through nozzles 8 should bemaintained in a finely divided but still liquid form the equipment 2seems to be no longer necessary as it is shown in the drawing. In suchcase the liquid fuel is heated in a suitable apparatus to the desiredtemperature and afterwards is injected under pressure by the respectivenozzles into the reaction chamber.

Having now described the invention and in what manner the same is to beperformed it is to be understood that the invention may be variouslyembodied within the scope of the claims hereinafter made.

What I claim is:

1. A process for the production of combustible gases from fuel which isliquid at ordinary temperatures comprising preheating said fuel,suspending a portion of said preheated fuel in free-oxygen-containinggas, injecting said suspension into a reaction chamber maintained at atemperature above the ignition temperature of said fuel, subjecting atleast a portion of said suspended fuel to ignition and combustion toform hot gaseous combustion products, separately injecting an additionalportion of said preheated fuel into the reaction chamber at a pointspaced above the point of introduction of said suspension andsubstantially immediately contacting the additional portion of saidpreheated fuel with the hot gaseous combustion products, therebysubjecting said additional portion of fuel to cracking, and withdrawingcombustible gases from the upper portion of the reaction chamber.

2. The process of claim 1 in which the additional portion of said fuelis injected into the reaction chamber in the form of a liquid spray.

3. The process of claim 1 in which the additional portion of said fuelis injected into the reaction chamber in the form of a vapor.

4. A process for the production of combustible gases from fuel which isliquid at ordinary temperatures comprising the steps of heating saidfuel to vaporize a portion thereof, dividing the unvaporized portioninto a plurality of streams, injecting the fuel in each of said streamsin the form of a suspension in a free-oxygen-containing gas into areaction chamber maintained at a temperature above the ignitiontemperature of said fuel, subjecting at least a portion of said fuelfrom said stream to ignition and combustion toform hot gaseouscombustion products, separately injecting the vaporized portion of saidfuel into the reaction chamber at a point spaced above the points ofintroduction of the suspensions and substantially immediately contactingthe vaporized portion of said fuel with the hot gaseous combustionproducts thereby subjecting said vaporized portion to cracking, andwithdrawing combustible gases from the upper portion of the reactionchamber.

5. The process of claim 4 in which at least a portion of the preheatingof said liquid fuel is accomplished by passing the combustible gases inindirect heat exchange with said liquid fuel.

6. The process of claim 4 in which the vaporized fuel is injected intothe reaction chamber in a plurality of streams.

7. The process of claim 6 in which the direction of flow of said streamsof vaporized fuel is perpendicular to the direction of flow of said hotgaseous products of combustion.

8. Apparatus for the production of combustible gases from liquid fuelcomprising in combination a vertical reaction chamber, a heater adaptedto contain and heat said fuel, outlets in the upper and lower portionsof said heater, an outlet in the upper portion of said reaction chamberand injector means in the middle and lower portions of said reactionchamber, the upper and lower outlets of said heater being connected tothe middle and lower injector means of said reaction chamberrespectively and gas inlet means leading into said lower injector meanswhereby the liquid fuel may be injected into the reaction chamber in theform of a suspension, said lower injector means comprising a pluralityof nozzles spaced around the periphery of the reaction chamber.

9. The apparatus of claim 8 in which the outlet end of each of saidnozzles is located within a recess in the wall of the reaction chamber,each of said recesses having the shape of a truncated cone, the largerend thereof being adjacent to and opening into the reaction chamber.

References Cited in the file of this patent UNITED STATES PATENTS549,515 Kendall Nov. 12, 1895 1,723,418 Hackford Aug. 6, 1929 1,836,627Suffern Dec. 15, 1931 1,904,908 Voorhees Apr. 18, 1933 1,983,992 PyzelDec. 11, 1934 2,423,527 Steinschlaeger July 8, 1947 2,568,351 MilbourneSept. 18, 1951- 2,582,938 Eastman et al. Jan. 15, 1952

1. A PROCESS FOR THE PRODUCTION OF COMBUSTIBLE GASES FROM FUEL WHICH ISLIQUID AT ORDINARY TEMPERATURES COMPRISING PREHEATING SAID FUEL,SUSPENDING A PORTION OF SAID PREHEATED FUEL IN FREE OXYGEN-CONTAININGGAS, INJECTING SAID SUSPENSION INTO A REACTION CHAMBER MAINTAINED AT ATEMPERATURE ABOVE THE IGNITION TEMPERATURE OF SAID FUEL, SUBJECTING ATLEAST A PORTION OF SAID SUSPENDED FUEL TO IGNITION AND COMBUSTION TOFORM HOT GASEOUS COMBUSTION PRODUCTS, SEPARATELY INJECTING AN ADDITIONALPORTION OF SAID PREHEATED FUEL INTO THE REACTION CHAMBER AT A POINTSPACED ABOVE THE POINT OF INTRODUCTION OF SAID SUSPENSION ANDSUBSTANTIALLY IMMEDIATELY CONTACTING THE ADDITIONAL PORTION OF SAIDPREHEATED FUEL WITH THE HOT GASEOUS COMBUSTION PRODUCTS, THEREBYSUBJECTING SAID ADDITIONAL PORTION OF FUEL TO CRACKING, AND WITHDRAWINGCOMBUSTIBLE GASES FROM THE UPPER PORTION OF THE REACTION CHAMBER.